Yes the new blouse fitting is TONS better. I anticipated that it would look much better when posed and animated. Again, good job!

I can't imagine even doing 127 different button morphs, nevermind 127 different morph objects. 

As for keeping fabrics together during simulation, you'd have to experiment with the Soft Decorated Group and Rigid Decorated Group options in the cloth room. I'd start with assigning both front and back plackets to the soft decorated, and the buttons to rigid decorated. See if that helps.